Use only one instance of FFPMEG per SRT stream instead of one per additional cast

stream/multicast/muticast.go

@@ -13,8 +13,8 @@ type Options struct {
 
 var (
 	options            Options
-	ffmpegInstances    = make(map[string][]*exec.Cmd)
-	ffmpegInputStreams = make(map[string][]*io.WriteCloser)
+	ffmpegInstances    = make(map[string]*exec.Cmd)
+	ffmpegInputStreams = make(map[string]*io.WriteCloser)
 )
 
 // New Load configuration
@@ -25,71 +25,70 @@ func New(cfg *Options) error {
 
 // RegisterStream Declare a new open stream and create ffmpeg instances
 func RegisterStream(streamKey string) {
-	ffmpegInstances[streamKey] = []*exec.Cmd{}
-	ffmpegInputStreams[streamKey] = []*io.WriteCloser{}
+	if len(options.Outputs[streamKey]) == 0 {
+		return
+	}
 
-	// TODO Export the list of multicasts
+	params := []string{"-re", "-i", "pipe:0"}
 	for _, stream := range options.Outputs[streamKey] {
-		// Launch FFMPEG instance
 		// TODO Set optimal parameters
-		ffmpeg := exec.Command("ffmpeg", "-re", "-i", "pipe:0", "-f", "flv", "-c:v", "libx264", "-preset",
+		params = append(params, "-f", "flv", "-c:v", "libx264", "-preset",
 			"veryfast", "-maxrate", "3000k", "-bufsize", "6000k", "-pix_fmt", "yuv420p", "-g", "50", "-c:a", "aac",
 			"-b:a", "160k", "-ac", "2", "-ar", "44100", stream)
-
-		// Open pipes
-		input, err := ffmpeg.StdinPipe()
-		if err != nil {
-			panic(err)
-		}
-		output, err := ffmpeg.StdoutPipe()
-		if err != nil {
-			panic(err)
-		}
-		errOutput, err := ffmpeg.StderrPipe()
-		if err != nil {
-			panic(err)
-		}
-		ffmpegInstances[streamKey] = append(ffmpegInstances[streamKey], ffmpeg)
-		ffmpegInputStreams[streamKey] = append(ffmpegInputStreams[streamKey], &input)
-
-		if err := ffmpeg.Start(); err != nil {
-			panic(err)
-		}
-
-		// Log ffmpeg output
-		go func() {
-			scanner := bufio.NewScanner(output)
-			for scanner.Scan() {
-				log.Println("[FFMPEG " + streamKey + "] " + scanner.Text())
-			}
-		}()
-		// Log also error output
-		go func() {
-			scanner := bufio.NewScanner(errOutput)
-			for scanner.Scan() {
-				log.Println("[FFMPEG ERROR " + streamKey + "] " + scanner.Text())
-			}
-		}()
 	}
+	// Launch FFMPEG instance
+	ffmpeg := exec.Command("ffmpeg", params...)
+
+	// Open pipes
+	input, err := ffmpeg.StdinPipe()
+	if err != nil {
+		panic(err)
+	}
+	output, err := ffmpeg.StdoutPipe()
+	if err != nil {
+		panic(err)
+	}
+	errOutput, err := ffmpeg.StderrPipe()
+	if err != nil {
+		panic(err)
+	}
+	ffmpegInstances[streamKey] = ffmpeg
+	ffmpegInputStreams[streamKey] = &input
+
+	if err := ffmpeg.Start(); err != nil {
+		panic(err)
+	}
+
+	// Log ffmpeg output
+	go func() {
+		scanner := bufio.NewScanner(output)
+		for scanner.Scan() {
+			log.Println("[FFMPEG " + streamKey + "] " + scanner.Text())
+		}
+	}()
+	// Log also error output
+	go func() {
+		scanner := bufio.NewScanner(errOutput)
+		for scanner.Scan() {
+			log.Println("[FFMPEG ERROR " + streamKey + "] " + scanner.Text())
+		}
+	}()
 }
 
 // SendPacket When a SRT packet is received, transmit it to all FFMPEG instances related to the stream key
 func SendPacket(streamKey string, data []byte) {
-	for _, stdin := range ffmpegInputStreams[streamKey] {
-		_, err := (*stdin).Write(data)
-		if err != nil {
-			log.Println("Error while sending a packet to external streaming server for key "+streamKey, err)
-		}
+	stdin := ffmpegInputStreams[streamKey]
+	_, err := (*stdin).Write(data)
+	if err != nil {
+		log.Println("Error while sending a packet to external streaming server for key "+streamKey, err)
 	}
-
 }
 
 // CloseConnection When the stream is ended, close FFMPEG instances
 func CloseConnection(streamKey string) {
-	for _, ffmpeg := range ffmpegInstances[streamKey] {
-		if err := ffmpeg.Process.Kill(); err != nil {
-			panic(err)
-		}
+	ffmpeg := ffmpegInstances[streamKey]
+	if err := ffmpeg.Process.Kill(); err != nil {
+		panic(err)
 	}
 	delete(ffmpegInstances, streamKey)
 	delete(ffmpegInputStreams, streamKey)